Preheating apparatus



Dec. 25, 1934. w D, YERRICK 1,985,269

PREHEATING APPARATUS Filed Feb. 5, 1931 4 Sheets-Sheet 2 VEN TOR.

flwa r I %25% %x ATTORNEY Dec. 25, 1934; w. D. YERRICK PREHEATING APPARATUS Filed Feb. 5, 1951 4 Sheets-Sheet 4 xs A TTORNEY A VEYT R. wi/%za Patented Dec. 25, 1934 particularity; in the appended claims. l \4 L 'mg, 1 side elevation' ,*partlv wat ngwa;

Air Preheater Corporation, aacorporation o! New York l present invention'relates to heat exchangers, and has particular* reference to heat ex changers ofthe. "regenerative type suitable for preheating L ai lfor .power plant and' industrial plant usell n v-.. V v t Modern pow rand industrial'plant development has stressed efiiciency of operation, and'has thereforedevelopedcontrol 'apparatus' 'Sensitive to very slight changes operatingconditions. It there-'- fore results that `slight`jchangs in the supply 'of heated air, or interruptions in the supply, produce undesirahle` operation effectsn It `has ,therefore become advi'sable to .devise 'auxiliary appajrtus, such as airgpreheaters, which will ensureza; substantially constant flowcfheated air; with sub.-` stantially no interruption,

u ,The devising of -'ali preheaters" with substantiallynconstant flow beengdiflicult; however,

;due tothe 'limited amount of' available' space in the modern *power or'industrial plart'and the necessity for increasing the preheater' loading as th ant load is`-increased.` The preferred preheater construction is therefore one to which units may bereadily 'added or removed' as' required, and which has it's regenerative material positioned to facilitate' inspection, 'replacement l and repair. v. w 1 in A further dimculty in planning' air preheaters for modern plants resides inthe tendency *to utilize cheaper fuel, in order to] decrease operating costslow priced fuels have more dust, and form more soot and deleterious' gasesand fumes. The preferred ,preheater construction "is therefore equipped withjfsoot blowing *apparatus formed asanintegral part thereof.j L j I j With these and 'other adv 'ntageous features in view, my invention consists of a novel arrangelment or parts disclosed 'mo'r'e 'fully in'the detailed description ronowing; ini 'conjunction' with' the accompanying drawings, defined with irnore m' 'the dr'awings':

of the' novel preheater;

Fig. 2 is' a Fi'g. 3 is a centraltransverse section through o preheater n z 4 Fig. 4 'is an enlarged elevation of one vane with 'one plate remov'ed;

l Fig. 5 is a section therethro gh on the line 5-5 of..`1'-''gure.'4;,.

Fig. 6' is a"frag mentary'e1evation of a modified preheater equipped with 'intermittent actuating mechanism, partly broken away; j

central vertical section through Fig- 1931'. set

i ce'ntia trt a section through Fig- .Fig.- 'a' isfinnargeivwr the interrnittent reduction mechanism; -Fig, 9 is a detail view inga modified arrangement =-Ithas been found desir ble a. series of adjacent preheaterunits,

preheater -as 'and H p Similar t'o 6,' but showto constructan air thus providing an. extended-[installation of small Width sui t able for positioningin back of .a boiler or the like, in the pathof the ,flue gases. It ,has also beeniound advantageous to mount the valves controlling each unit 'so as` to facilitate common actuation, thus simplif'ying the necessary actuating mecha'nism; The following is a detailed de: scription of a preferred preheater 'arrangement .embody g ,the principl es of my invention.

The preheater, as shown in Figures 1 and 2, includes a casing 1 which is provided with suitable openings for inspection. and` repair; normally closed by covers 1 1`.` a Thepreheater hasa number of fixed vertica1 partitions 12 between which re-` generative material 13 isfmounted in any desired manner to provide ;flow passages for the air and gas the preferred form comprising regenerative not shown, on the side regenerative material plates which'are--seated onlshoulders or flanges,

walls ofthe casing. The is preferablvrnount'ed to present a concave upper andlower surface m each unit, as shownin Figure 2.

The upper wall 14Aand the lower wall lhave vertical standards 16, 17 extendingtherefrom, po-

sitioned intermediate each preheater unit, the

standards 16 serving as separating Iwalls ,between the cold airjinlet flow chambers 18 and the cold gas outlet flow chambersdg and the standards '17 serving as separatings walls between' the hot gas inlet flow chambers- 20 and the hot air c'iutlet` flow chambers 21. .These inletandoutlet chambers, together with the preheater passages form air and gas flow passageways "which communicate i .withcominonmanifold s, which are easily mount- `e`d on suitable fian'g'es,"`as shown at 22 in ,Figures l anda, and are. designated "as 2.3, 24, 25.and 26. Vanes 27are pivotally mounted in theside walls of the'casing, and cooperate' with the standards 16 and 17 to form guide Ways for the passage of theair 'and the iiue gases through the regenerative material; Asindicatedjin Figure 2, the' upper 'and lower vanes are mountedto swing" in parallel a1ignm`ent,`withthe free ends of the juxtaposed i Vanes always substantiallyin* ve'rtical alignment, but not in exact alig'r'ment, for the purpose here- `inafter described.

ures 1 9 h casing 'o is shown as formed of three Sections, 28, 29 and 30, having flanges for securing the Sections together into a unitary structure. This construction facilitates manufacture, assembly, and repair. The vanes 27 are pivotally mounted in the side walls of the end Sections 28, 30, and include an upper horizontal conduit 31, an intermediate vertca conduit' 32,- a lowerhorizontal c'onduit 33;'an d two cover plates 34 which 'are mounted over the 'conduits, as shown in Figure 5. Each conduit 31 has a swivel connection 35 swivelled at one end there of, and an operating lever 36 securedtoandsealing the other end thereof. The conduit' 33 'slit' at the lower portion thereof, as shown in 'Fi ure,

and a slotted bar 37 is mounted'therein, to serve as a no-zzle slot for scavenging fiuid. Sealing strips 38 are secured to thelower ends oi the cover plates 34, and are adapted to sweep over the ends of the regenerative material 13, which-.as shown in Figure 3 is preferably separatedintotwoportio'ns by' a' vertical partition 39`to facitateassem bly and repairs, The partitions 16, 1 '7 may*'have bearing Sections to 'receive theconduits 3 1'," as shown in Figure 2. v f 1 The operati'ng inechanis'm' for oscillat mg the vanes is shown in Figure 1, and includes'iods or bars'40 secured'to'thfree ends'of theflevers 36, and oscillated upon'swinging movements of angle plates 41 pivot'ed to the"caslng 10 as'at 42'. The

angle plates ii'ar swung'by'rods 'segcured to a crank 44 oi' the like', adapted to' be rotated upon rotation of a suitable motor, not' shown; actin' througha speed reducer 45, N t

The operation *of the' specific preheater* above described is as followsz* i 4 "Theho't fiue gases enter through the common hot gas inlet manifold, and'pass'through; chambers 20, between the lower; guide vanes' 27,' through ,selected portionsl of'the regenrative material '13, then' between 'the 'upper, guidevanes '27' and through the 'outle't' ,chambers 19 to' the common outlet manifold. The cold air enters throughthe air 'inletmanifoldand inga, Similar manner descends downwardly through'ch'ambers 18, between upper vanes 27,, 'through selctedportions' of the regnerative material, 'between lower guide vanes 27, and out" through' hot air outlet* chambers 2-1' and the common outle't manifold. 'The vanes 2'7 'continually swin'g over the upperand lower sur faces of the regenerative material, which has the usuar through passages formed by the well-known use of alternate fiat and corrugatedregenerative plates, thus altenately'including these through passa'ges inthe 'hot ga'sand the aii* flowpassage- Ways, the 'area *of the fiowpassageways' remaining constant, and thus providing-'a constantst'pply of hot air with no lflow interruption's. V As the vanes move, scavenging fluid under pressure', such as steam, ma'y'be passed through the conduits of 'the ,upper orf'lower vanes, or both, the upper 'and'lower vanes being'jslightly displacedto provide free passage of the scavenging" fluid. It is usually sufli'cien't to utilize but oneset of vanes as scavengin'gwvanes, the 'sca'v enging fluid'being blown out to'form part of the cooled'fiue g'ases.

Althou gh ,aslowuswing ing movement' of, the vanes 2.7, is'preferred, assuch moveihent 'main-.- tains a Constant flowarea, certain installations v may require snap movementof the. vanes,. A construction suitable for this purpose .is 'shown in Figures G to8, the vanes 46 being of the straight plate* type-,with end bufier pieces 47., and theregenerative material 48 being ofniorm height and. mounted betweenseparatng partition's-f49 which extend beyond the regeneratve material to be engaged by the bufier pieces 47. The operating mechanism, in this construction, includes levers 50 secured to one end of the shafts 51 of the vanes, sWing rods or bars 52 secured to the free ends of the levers 50, angle plates 53 pivoted at one corner to the casing, the two angle plates being connected by a rod 54, and mechanism ;for intermittently oscillating the upper angle plate including a motor 55, a speed reducer 56, 23', crank 57 connected by means of a rod 58 to a ratchet ver 59 rotatably mounted on a shaft 60, the ratchet lever, having a pawl 61 piVoted thereto as at 62 and rotated by the -operating connections to move' over two notcheddisks 63, 64, which are respeetively' rotatably mounted on and keyed to the shaft 60.

; Thenotchesin the .disk 64, which is smaller than dish 63, are V-shaped, as indicated at 65;

the disk 63 has Similar notches 66, which extend only to the ,rim of the Wheel 64, and one double notch 67; into which the pawl' 6l"extends to; also engage With a no tch' to shift'the disk' i'once during a complete rotation'ot thefdisk 63'. "The disk 64, which is key'ed to the shaft 60,*thus ro' tates a gear Wheel 68 which is also keyed to' the shaft 60; a gearw eei 59' is 'm shed With the 'gear Wheel 68, 'and rotates abi'atkfidw'hich isconnected to the 'upper' late 53 byafcinectngrod 71. The described construction provides; a quick movement. of the vanes, foilowe'd by a'long'j'dw'ell', aha thls pfoyides a' substantiaflly onstant flow oi' air'fwith only a monentaryf interruption during* shifting of jthe vanes." ;If :dsir: ,the ratchet mechanism described' may *bef applie'd 'to each shaft '51,111 displacedphase; sothat the vanes of each unit will shift in'sjuccession, afl'z g a plurality of arrangements such as in Figs. 6 and 8, with individual platesi53c'j53b,%530, etc., which t are connected to 'separate lever's 50% 5015; o'cetclgby means of separate swingjbars 52a, `j2b, 52e, etc. 'Ihis'constructionis of, advantage in' 'nstallations where'the capacity of the preheat er' isi greatly in excess of ,the lead. j v ;The air .preheater constructidn' described (is simple to 'manufactur'e, nstall and repainmay* be readily enla'rge'd" by adding additional luhts-;cccupies, very little space in comparison' tits lead rating; and ensure'sa substa'ntially constant sup: .pIy of heatedair; While I have esjrib d 'specific embodiments off y preheatersisuch changes 'in shape, in arrangemenjt of parts, in op'erating te turesxand the like as' maybej desirable* to' uit the requirements of individual instalatinsjiay. ob- Viously be made, within the Spirit and thescope 'of the inyention, as definedjinthe appended claims.

1". In anair preheate'r, a casna a plurality "of `adjacc-nt heat transfer chambersin said'casing Separ'ated by partitins, a' pluralityof' air flow chambers and 'gas flow chambers mounted in al ternate adja'c'e'ncyon each side' of said heat 'tra-'ns fer chambers and separated by'standardsgswing- `ing guide vanes mount'edon said flow chamber standards and engageable'jWithfsaidsparating ing guide vanes for alternately guidng the air and the gas through selected flow passages of said heat transfer chambers, mechanism for intermittently swinging said guide vanes, and means on at least some of said swinging vanes for scavenging said heat exchange chambers.

3. In an air preheater, a casing, partitions separating the upper and lower portions of said casing into alternate air and gas flow chambers, a plurality of chambers having separating partitions and containing heat exchange material positioned intermediate said casing between said upper and lower flow chambers, swinging vanes forming continuations of said flow chamber partitions and engageable with said separating partitions to alternately communicate said heat exchange chambers with the upper and lower air flow chambers, and the upper and lower gas flow chambers and mechanism for intermittently swinging said guide vanes successively in sequence. 4

4. In an air preheater, a plurality of heat exchange chambers containing regenerative material, air inlet and outlet manifolds, gas inlet and outlet manifolds, means for alternately communicating said chambers with said air manifolds and said gas manifolds, and means for timing said communication means for the several chambers to operate in sequence.

. WILLIAM D. YERRICK. 

